MACC. Support to civil logistics and infrastructure. Petrol stations running out of fuel has a huge economic impact as well as the threat of civil unrest because of it. 80 HGV drivers is no big deal in the grand scheme of things for the military and pales into insignificance when compared to the demands of the Olympics. I'm surprised it's only 80 drivers being called on to be honest. Yes it is proper use of UK military personnel.
Who's going to fill the aircraft? The same civvies that do it now probably